Array-ness of columns is completely ignored

```sql
-- in table `articles`
tags character varying(40)[]
```

What gets added:
```ruby
# in model `Article`
validates_length_of :tags, maximum: 40
```

So instead of limiting each item in the array to 40 characters, we limit the array to 40 items!

A quick fix would be skipping adding validations for attributes where `column.array?` is `true`.


